Letter to the Editor

Identification of 8 INTEGRAL hard X-ray sources with Chandra

¹ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85740 Garching bei München, Germany e-mail: sazonov@mpa-garching.mpg.de
² Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, USA

Received: 29 August 2005
Accepted: 22 October 2005

Abstract

We report the results of identification of 8 hard X-ray sources discovered by the INTEGRAL observatory during the ongoing all-sky survey. These sources have been observed by Chandra. In 6 cases a bright X-ray source was found within the INTEGRAL localization region, which permitted to unambiguously identify 5 of the objects with nearby galaxies, implying that they have an active galactic nucleus (AGN), whereas one source is likely an X-ray binary in LMC. 4 of the 5 newly discovered AGNs have measured redshifts in the range 0.025–0.055. The X-ray spectra reveal the presence of significant amounts of absorbing gas ( in the range 10²²–10²⁴ cm^-2) in all 5 AGNs, demonstrating that INTEGRAL is starting to fill in the sample of nearby obscured AGNs.